The O-silylation of alcohol is very important in organic synthesis. The reason is that, because the proton of alcohol reacts with a nucleophilic reagent in organic synthesis, the hydroxyl group of alcohol should be replaced by a protective group in order to block this reaction, and silylation of the hydroxylic group of alcohol can block this reaction, and is thus useful for the protection of alcohol. Because of this advantage, many O-silylation reactions have been studied and developed. However, most of the O-silylation reactions have a problem in that they should be used only in water-free conditions because they employ chlorosilane, hydrosilane and the like, which are highly reactive and are sensitive to water and the like. Also, because a stoichiometric amount of tertiary amine should be used as a proton acceptor, an amount of ammonium salt more than a stoichiometric amount is produced after the silylation reaction, and the removal thereof becomes a great problem.
Moreover, it is important in developing organic/inorganic hybrids to tightly link an organic compound to a solid surface, and the use of covalent bonding for such linkage is considered to be the most reliable method for surface modification.
A typical example is covalent bonding between solid silica, as a solid surface, and an organic compound, in which a silicon atom present on the surface of silica forms a Si—O—Si bond with the silicon atom of an organic silicon compound. Specifically, a Si—OH group on the silica surface reacts with the organic silicon compound, which has a leaving group such as a halide, alkoxy or an amino group on the silicon atom thereof, so as to form a Si—O—Si covalent bond.
In a sol-gel synthesis method, which is most widely known as an organic-inorganic hybrid synthesis method, trialkoxysilane is used to form a siloxane network through hydrolysis and condensation, thus immobilizing a functional group. This method has shortcomings in that it is difficult to introduce organic macromolecules, because alkoxysilane is sensitive to water, making it impossible to separate alkoxysilane through column chromatography, and when a functional group is located inside the network, it will be lost. Also, there is a shortcoming in that it is difficult to introduce bioactive molecules, such as natural compounds and proteins, due to the pH environment of a hydrolysis process which is a necessary process of the sol-gel method. As an alternative thereto, there is a grafting method of linking compounds directly to a solid support. This overcomes the shortcomings of the sol-gel method, but has problems in that it has a low loading rate in practical use and in that it is not easy to control functional groups.
To solve such shortcomings, a method including the use of an allylsilane organic compound, which is relatively stable in water, was recently developed, but it has a problem in that it requires high-temperature reflux to conduct the reaction, and thus it is difficult to apply to organic silicon compounds containing thermally sensitive organic groups.